Thin Film Transistor Liquid Crystal Display (TFT-LCD) is an important flat panel display device. The display device generally includes a display panel, which generally comprises an array substrate TFT and a color filter (CF) substrate which are arranged as aligned, wherein the main structure of the color filter substrate (for example, IPS) includes a glass substrate, a ITO conductive film on the back side, a black Matrix (BM), a color resist layer (which includes a red color fitter, a green color fitter and a blue color fitter) RGB, an over coating (OC), and columnar spacer.
However, the conventional method for preparing a color filter substrate has been found the following disadvantages in practice: the uniformity of film thickness of the color filter substrate is poor, and the flatness of the over coating OC is low, and there are various risks during the aligning process with the TFT substrate, causing bad incidence greatly increased.
For this reason, now there is an urgent need for a preparation method capable of satisfying the flatness requirement of the over coating OC and greatly improving the film thickness uniformity of the display substrate (such as a color filter substrate).